I've seen this cited a few times when having this argument.
He was honest from the get go, was not considering offers from other English clubs (I think Juve and Bayern were said to be asking about him), didn't cite a "lack of ambition" from the club, and Alex Ferguson. 50k per week for a peak Roy Keane was, as the feeling at the time, well worth the money anyway. In addition to that, United had just won the CL but still had strict wage budgets when compared to other clubs in the continent. We broke our wage ceiling for him, paving the way for us to sign Veron (who despite his failure at the club, was seen as a true world class player at the time) a few months later.
Different frog, different times.